Event notification

ABSTRACT

In one embodiment, a method includes while a user is interacting with a mobile device, displaying a notification on a screen of the mobile device automatically and without any user input to the mobile device, the notification informing the user an event that has occurred recently and is not related to the user&#39;s interaction with the mobile device.

TECHNICAL FIELD

This disclosure generally relates to a user interface.

BACKGROUND

A user interface (UI), in the industrial design field of human-machine interaction, is the space where interactions between humans and machines occur. The goal of the interactions between a human, often referred to as a “user”, and a machine at the user interface is the user's control of the machine and its operations (e.g., through user input) and machine feedback (e.g., through program output). A graphical user interface (GUI) is a type of user interface that allows users to interact with software applications executing on electronic or computing devices through multimedia objects (e.g., images, videos, audios, etc.) rather than purely text commands.

SUMMARY OF PARTICULAR EMBODIMENTS

In particular embodiments, a user interface for presenting content to users may have a hierarchical structure. The user interface may have any number of content sections, and each content section may have any number of content items. The content items may be of any type or format. A user may consume or interact with some of the content items. In particular embodiments, each content item may correspond to a user-interface element.

In particular embodiments, while a user is interacting with a mobile device, event notifications may, from time to time, appear on the screen of the mobile device automatically and without any user input to the mobile device. Each notification informs the user of an event that has occurred recently (e.g., within the past minute). Each notification may remain on the screen of the mobile device for a short period of time (e.g., ten seconds), and then disappears.

In particular embodiments, the events described in the notifications are not necessarily related to the user's interaction with the mobile device. Instead, for example, each notification may inform the user of a recent action taken by or concerning another user. With some implementations, both the user and the other user are members of a social-networking system and are friends within the social-networking system. The action the other user has taken may be through the social-networking system. Consequently, the user is kept informed of the actions taken by his friends within the social-networking system (i.e., the other users) in near real time.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example network environment associated with a social-networking system.

FIGS. 2A and 2B illustrate two example mobile electronic devices.

FIG. 3 illustrates an example social graph.

FIG. 4 illustrates an example object hierarchy.

FIG. 5 illustrates an example event notification.

FIG. 6 illustrates an example event notification.

FIG. 7 illustrates an example event notification.

FIG. 8 illustrates an example event notification.

FIG. 9 illustrates an example series of event notifications arranged in reverse chronological order.

FIG. 10 illustrates an example computer system.

DESCRIPTION OF EXAMPLE EMBODIMENTS

A user interface (UI) may be incorporated into any type of software applications, including, for example, desktop applications, mobile applications, or web-based applications, to enable users to interact with and control the applications. A graphical user interface (GUI) is a type of user interface that enables users to interact with software applications through multimedia objects, including, for example, icons, buttons, menus, images, video, or audios.

In particular embodiments, a software application may be associated with a social-networking system. FIG. 1 illustrates an example network environment 100 associated with a social-networking system. Network environment 100 includes a user 101, a client system 130, a social-networking system 160, and a third-party system 170 connected to each other by a network 110. Although FIG. 1 illustrates a particular arrangement of user 101, client system 130, social-networking system 160, third-party system 170, and network 110, this disclosure contemplates any suitable arrangement of user 101, client system 130, social-networking system 160, third-party system 170, and network 110. As an example and not by way of limitation, two or more of client system 130, social-networking system 160, and third-party system 170 may be connected to each other directly, bypassing network 110. As another example, two or more of client system 130, social-networking system 160, and third-party system 170 may be physically or logically co-located with each other in whole or in part. Moreover, although FIG. 1 illustrates a particular number of users 101, client systems 130, social-networking systems 160, third-party systems 170, and networks 110, this disclosure contemplates any suitable number of users 101, client systems 130, social-networking systems 160, third-party systems 170, and networks 110. As an example and not by way of limitation, network environment 100 may include multiple users 101, client system 130, social-networking systems 160, third-party systems 170, and networks 110.

In particular embodiments, user 101 may be an individual (human user), an entity (e.g., an enterprise, business, or third-party application), or a group (e.g., of individuals or entities) that interacts or communicates with or over social-networking system 160. In particular embodiments, social-networking system 160 may be a network-addressable computing system hosting an online social network. Social-networking system 160 may generate, store, receive, and transmit social-networking data, such as, for example, user-profile data, concept-profile data, social-graph information, or other suitable data related to the online social network. Social-networking system 160 may be accessed by the other components of network environment 100 either directly or via network 110. In particular embodiments, social-networking system 160 may include an authorization server that allows users 101 to opt in or opt out of having their actions logged by social-networking system 160 or shared with other systems (e.g., third-party systems 170), such as, for example, by setting appropriate privacy settings. In particular embodiments, third-party system 170 may be a network-addressable computing system that can host various third-party software applications (e.g., web-based applications). Third-party system 170 may generate, store, receive, and transmit various types of data, such as, for example, texts, images, videos, or audios. Third-party system 170 may be accessed by the other components of network environment 100 either directly or via network 110. In particular embodiments, one or more users 101 may use one or more client systems 130 to access, send data to, and receive data from social-networking system 160 or third-party system 170. Client system 130 may access social-networking system 160 or third-party system 170 directly, via network 110, or via a third-party system. As an example and not by way of limitation, client system 130 may access third-party system 170 via social-networking system 160. Client system 130 may be any suitable computing device, such as, for example, a personal computer, a laptop computer, a cellular telephone, a smartphone, or a tablet computer.

This disclosure contemplates any suitable network 110. As an example and not by way of limitation, one or more portions of network 110 may include an ad hoc network, an intranet, an extranet, a virtual private network (VPN), a local area network (LAN), a wireless LAN (WLAN), a wide area network (WAN), a wireless WAN (WWAN), a metropolitan area network (MAN), a portion of the Internet, a portion of the Public Switched Telephone Network (PSTN), a cellular telephone network, or a combination of two or more of these. Network 110 may include one or more networks 110.

Links 150 may connect client system 130, social-networking system 160, and third-party system 170 to communication network 110 or to each other. This disclosure contemplates any suitable links 150. In particular embodiments, one or more links 150 include one or more wireline (such as for example Digital Subscriber Line (DSL) or Data Over Cable Service Interface Specification (DOCSIS)), wireless (such as for example Wi-Fi or Worldwide Interoperability for Microwave Access (WiMAX)), or optical (such as for example Synchronous Optical Network (SONET) or Synchronous Digital Hierarchy (SDH)) links. In particular embodiments, one or more links 150 each include an ad hoc network, an intranet, an extranet, a VPN, a LAN, a WLAN, a WAN, a WWAN, a MAN, a portion of the Internet, a portion of the PSTN, a cellular technology-based network, a satellite communications technology-based network, another link 150, or a combination of two or more such links 150. Links 150 need not necessarily be the same throughout network environment 100. One or more first links 150 may differ in one or more respects from one or more second links 150.

In particular embodiments, data (e.g., data representing various types of information or content) may be sent between servers associated with social-networking system 160 and individual client systems 130 via network 110. When two electronic devices (e.g., a server and a client) are connected to a network (e.g., a computer or communications network, such as network 110), data may be transmitted between the two devices over the network using one or more suitable network protocols. A network may include any number of sub-networks. By transmitting data between the two devices, the two devices may communicate with each other.

In network communications, there are two ways to send a communication (i.e., data) from one device to another device: push and pull. With push technology, the request for the communication transaction is initiated by the sending device. That is, the sending device “pushes” the communication, so to speak, to the receiving device. In this case, the sending device may be considered the active party and the receiving device may be considered the passive party in the transaction. In contrast, with pull technology, the request for the communication transaction is initiated by the receiving device. That is, the receiving device “pulls” the communication, so to speak, from the sending device. In this case, the sending device may be considered the passive party and the receiving device may be considered the active party in the transaction. In particular embodiments, a server associated with social-networking system 160 may push data to a client system 130. A communication pushed from a server to a client may be referred to as a “push notification”. Similarly, a client system 130 may push data to a server associated with social-networking system 160.

In particular embodiments, a client system 130 may be a mobile electronic or computing device. A mobile electronic device—such as a Smartphone, tablet computer, or laptop computer—may include functionality for determining its location, direction, or orientation, such as a GPS receiver, compass, or gyroscope. Such a mobile device may also include functionality for wireless communication, such as BLUETOOTH communication, near-field communication (NFC), or infrared (IR) communication or communication with a wireless local area networks (WLANs) or cellular-telephone network. Such a mobile device may also include one or more cameras, scanners, touchscreens, microphones, or speakers. Mobile electronic devices may also execute software applications, such as games, web browsers, or social-networking applications. With social-networking applications, users may connect, communicate, and share information with other users in their social networks.

In particular embodiments, a mobile electronic device (e.g., Smartphone or tablet computer) may include a touchscreen capable of receiving touch input. FIG. 2A illustrates an example mobile electronic device 210 (e.g., a Smartphone) having a touchscreen 215. Touchscreen 215 may incorporate one or more touch sensors and a touch-sensor controller for detecting the presence and location of a touch (e.g., from a user's finger) or the proximity of an object (e.g., a stylus). In particular embodiments, a specific touch detected via touchscreen 215 may result in a touch input event.

Different mobile electronic devices may have different designs. As a result, the size, shape, or aspect ration of the touchscreens of different mobile devices may differ. FIG. 2B illustrates another example mobile electronic device 220 (e.g., a tablet computer) having a touchscreen 225. Similarly, touchscreen 225 may incorporate one or more touch sensors and a touch-sensor controller for detecting the presence and location of a touch (e.g., from a user's finger) or the proximity of an object (e.g., a stylus). A specific touch detected via touchscreen 225 may result in a touch input event. However, since mobile electronic devices 210 and 220 are two different types of devices, their respective touchscreen 215 and 225 have different sizes and aspect ratios.

There may be various types of touches or gestures, such as single tap, double tap, short press, long press, slide, swipe, flip, pinch open, or pinch close, corresponding to various types of touch input events. Different touch input events may result in different responses and this disclosure contemplates any applicable gesture.

Social-networking system 160 may store various types of data including, for example, user data, application data, or social data. In particular embodiments, such data may be stored in a graph having any number of nodes and edges, where each edge connects two nodes. The graph is often referred to as a “social graph” or “open graph” as it contains, among others, social information.

FIG. 3 illustrates example social graph 300. In particular embodiments, social-networking system 160 may store one or more social graphs 300 in one or more data stores. In particular embodiments, social graph 300 may include multiple nodes—which may include multiple user nodes 302 or multiple concept nodes 304—and multiple edges 306 connecting the nodes. Example social graph 300 illustrated in FIG. 3 is shown, for didactic purposes, in a two-dimensional visual map representation. In particular embodiments, a social-networking system 160, client system 130, or third-party system 170 may access social graph 300 and related social-graph information for suitable applications. The nodes and edges of social graph 300 may be stored as data objects, for example, in a data store (such as a social-graph database). Such a data store may include one or more searchable or queryable indexes of nodes or edges of social graph 300.

In particular embodiments, a user node 302 may correspond to a user of social-networking system 160. As an example and not by way of limitation, a user may be an individual (human user), an entity (e.g., an enterprise, business, or third-party application), or a group (e.g., of individuals or entities) that interacts or communicates with or over social-networking system 160. In particular embodiments, when a user registers for an account with social-networking system 160, social-networking system 160 may create a user node 302 corresponding to the user, and store the user node 302 in one or more data stores. Users and user nodes 302 described herein may, where appropriate, refer to registered users and user nodes 302 associated with registered users. In addition or as an alternative, users and user nodes 302 described herein may, where appropriate, refer to users that have not registered with social-networking system 160. In particular embodiments, a user node 302 may be associated with information provided by a user or information gathered by various systems, including social-networking system 160. As an example and not by way of limitation, a user may provide his or her name, profile picture, contact information, birth date, sex, marital status, family status, employment, education background, preferences, interests, or other demographic information. In particular embodiments, a user node 302 may be associated with one or more data objects corresponding to information associated with a user. In particular embodiments, a user node 302 may correspond to one or more webpages.

In particular embodiments, a concept node 304 may correspond to a concept. As an example and not by way of limitation, a concept may correspond to a place (such as, for example, a movie theater, restaurant, landmark, or city); a website (such as, for example, a website associated with social-network system 160 or a third-party website associated with a web-application server); an entity (such as, for example, a person, business, group, sports team, or celebrity); a resource (such as, for example, an audio file, video file, digital photo, text file, structured document, or application) which may be located within social-networking system 160 or on an external server, such as a web-application server; real or intellectual property (such as, for example, a sculpture, painting, movie, game, song, idea, photograph, or written work); a game; an activity; an idea or theory; another suitable concept; or two or more such concepts. A concept node 304 may be associated with information of a concept provided by a user or information gathered by various systems, including social-networking system 160. As an example and not by way of limitation, information of a concept may include a name or a title; one or more images (e.g., an image of the cover page of a book); a location (e.g., an address or a geographical location); a website (which may be associated with a URL); contact information (e.g., a phone number or an email address); other suitable concept information; or any suitable combination of such information. In particular embodiments, a concept node 304 may be associated with one or more data objects corresponding to information associated with concept node 304. In particular embodiments, a concept node 304 may correspond to one or more webpages.

In particular embodiments, a node in social graph 300 may represent or be represented by a webpage (which may be referred to as a “profile page”). Profile pages may be hosted by or accessible to social-networking system 160. Profile pages may also be hosted on third-party websites associated with a third-party server 170. As an example and not by way of limitation, a profile page corresponding to a particular external webpage may be the particular external webpage and the profile page may correspond to a particular concept node 304. Profile pages may be viewable by all or a selected subset of other users. As an example and not by way of limitation, a user node 302 may have a corresponding user-profile page in which the corresponding user may add content, make declarations, or otherwise express himself or herself. As another example and not by way of limitation, a concept node 304 may have a corresponding concept-profile page in which one or more users may add content, make declarations, or express themselves, particularly in relation to the concept corresponding to concept node 304.

In particular embodiments, a concept node 304 may represent a third-party webpage or resource hosted by a third-party system 170. The third-party webpage or resource may include, among other elements, content, a selectable or other icon, or other inter-actable object (which may be implemented, for example, in JavaScript, AJAX, or PHP codes) representing an action or activity. As an example and not by way of limitation, a third-party webpage may include a selectable icon such as “like,” “check in,” “eat,” “recommend,” or another suitable action or activity. A user viewing the third-party webpage may perform an action by selecting one of the icons (e.g., “eat”), causing a client system 130 to transmit to social-networking system 160 a message indicating the user's action. In response to the message, social-networking system 160 may create an edge (e.g., an “eat” edge) between a user node 302 corresponding to the user and a concept node 304 corresponding to the third-party webpage or resource and store edge 306 in one or more data stores.

In particular embodiments, a pair of nodes in social graph 300 may be connected to each other by one or more edges 306. An edge 306 connecting a pair of nodes may represent a relationship between the pair of nodes. In particular embodiments, an edge 306 may include or represent one or more data objects or attributes corresponding to the relationship between a pair of nodes. As an example and not by way of limitation, a first user may indicate that a second user is a “friend” of the first user. In response to this indication, social-networking system 160 may transmit a “friend request” to the second user. If the second user confirms the “friend request,” social-networking system 160 may create an edge 306 connecting the first user's user node 302 to the second user's user node 302 in social graph 300 and store edge 306 as social-graph information in one or more of data stores (e.g., data stores associated with social-networking system 160). In the example of FIG. 3, social graph 300 includes an edge 306 indicating a friend relation between user nodes 302 of user “A” and user “B” and an edge indicating a friend relation between user nodes 302 of user “C” and user “B.” Although this disclosure describes or illustrates particular edges 306 with particular attributes connecting particular user nodes 302, this disclosure contemplates any suitable edges 306 with any suitable attributes connecting user nodes 302. As an example and not by way of limitation, an edge 306 may represent a friendship, family relationship, business or employment relationship, fan relationship, follower relationship, visitor relationship, subscriber relationship, superior/subordinate relationship, reciprocal relationship, non-reciprocal relationship, another suitable type of relationship, or two or more such relationships. Moreover, although this disclosure generally describes nodes as being connected, this disclosure also describes users or concepts as being connected. Herein, references to users or concepts being connected may, where appropriate, refer to the nodes corresponding to those users or concepts being connected in social graph 300 by one or more edges 306.

In particular embodiments, an edge 306 between a user node 302 and a concept node 304 may represent a particular action or activity performed by a user associated with user node 302 toward a concept associated with a concept node 304. As an example and not by way of limitation, as illustrated in FIG. 3, a user may “like,” “attended,” “played,” “listened,” “cooked,” “worked at,” or “watched” a concept, each of which may correspond to a edge type or subtype. A concept-profile page corresponding to a concept node 304 may include, for example, a selectable “check in” icon (such as, for example, a clickable “check in” icon) or a selectable “add to favorites” icon. Similarly, after a user clicks these icons, social-networking system 160 may create a “favorite” edge or a “check in” edge in response to a user's action corresponding to a respective action. As another example and not by way of limitation, a user (user “C”) may listen to a particular song (“Ramble On”) using a particular application (SPOTIFY, which is an online music application). In this case, social-networking system 160 may create a “listened” edge 306 and a “used” edge (as illustrated in FIG. 3) between user nodes 302 corresponding to the user and concept nodes 304 corresponding to the song and application to indicate that the user listened to the song and used the application. Moreover, social-networking system 160 may create a “played” edge 306 (as illustrated in FIG. 3) between concept nodes 304 corresponding to the song and the application to indicate that the particular song was played by the particular application. In this case, “played” edge 306 corresponds to an action performed by an external application (SPOTIFY) on an external audio file (the song “Imagine”). Although this disclosure describes particular edges 306 with particular attributes connecting user nodes 302 and concept nodes 304, this disclosure contemplates any suitable edges 306 with any suitable attributes connecting user nodes 302 and concept nodes 304. Moreover, although this disclosure describes edges between a user node 302 and a concept node 304 representing a single relationship, this disclosure contemplates edges between a user node 302 and a concept node 304 representing one or more relationships. As an example and not by way of limitation, an edge 306 may represent both that a user likes and has used at a particular concept. Alternatively, another edge 306 may represent each type of relationship (or multiples of a single relationship) between a user node 302 and a concept node 304 (as illustrated in FIG. 3 between user node 302 for user “E” and concept node 304 for “SPOTIFY”).

In particular embodiments, social-networking system 160 may create an edge 306 between a user node 302 and a concept node 304 in social graph 300. As an example and not by way of limitation, a user viewing a concept-profile page (such as, for example, by using a web browser or a special-purpose application hosted by the user's client system 130) may indicate that he or she likes the concept represented by the concept node 304 by clicking or selecting a “Like” icon, which may cause the user's client system 130 to transmit to social-networking system 160 a message indicating the user's liking of the concept associated with the concept-profile page. In response to the message, social-networking system 160 may create an edge 306 between user node 302 associated with the user and concept node 304, as illustrated by “like” edge 306 between the user and concept node 304. In particular embodiments, social-networking system 160 may store an edge 306 in one or more data stores. In particular embodiments, an edge 306 may be automatically formed by social-networking system 160 in response to a particular user action. As an example and not by way of limitation, if a first user uploads a picture, watches a movie, or listens to a song, an edge 306 may be formed between user node 302 corresponding to the first user and concept nodes 304 corresponding to those concepts. Although this disclosure describes forming particular edges 306 in particular manners, this disclosure contemplates forming any suitable edges 306 in any suitable manner.

In particular embodiments, a set of objects may be organized into a hierarchy based on, for example, how the individual objects are related to each other. An object hierarchy may have any number of levels, and at each level, there may be any number of objects. Parent-child or sibling relationships may exist between specific objects in the hierarchy. Within an object hierarchy, a parent object is one level above the level of its child objects. Two sibling objects are at the same level and share the same parent object. In addition, any portion of the hierarchy may also be considered a hierarchy in itself.

FIG. 4 illustrates a portion of an example object hierarchy 400 that includes a number of objects 410. FIG. 4 is in fact a visual representation of an object hierarchy. Each node represents a specific object in the hierarchy, and each edge connecting two nodes represents a parent-child relationship between the two corresponding objects.

In particular embodiments, an object in a hierarchy may or may not have a parent. If an object does not have a parent, it may be referred to as a “root” object (e.g., object 410A). Typically, the root object is positioned at the first or topmost level of the hierarchy. In particular embodiments, an object in a hierarchy may or may not have any children. If an object does not have any children, it may be referred to as a “leaf” or “terminal” object (e.g., object 410B). If an object does have children (e.g., object 410C), it may have any number of children. In addition, objects sharing the same parent may be referred to as each other's “siblings”. For example, in FIG. 4, object 410C is the parent of objects 410D and 410B. Objects 410D and 410B are the children of object 410C and are siblings to each other. Thus, a hierarchy of objects (e.g., object hierarchy 400) not only includes the individual objects (e.g., objects 410) themselves but also indicates the relationships among the specific objects. Moreover, the position of a specific object within the hierarchy may indicate its relationships with other objects in the hierarchy.

Objects 410 may be of various types, and this disclosure contemplates any applicable object types. For example and without limitation, the term “object” may refer to any type of content, including but not limited to images, videos, captions, text blocks or boxes, user-interface elements, clickable links, newsfeed stories, references to other objects, advertisements, calendar events, units for displaying open graph analysis that may be graphically rendered, applications, websites, web pages, books, chapters. In particular embodiments, given a hierarchy of objects, which may be a portion of another, larger hierarchy of objects, the hierarchical relationships (e.g., parent-child or sibling relationships, positions of the objects within the hierarchy) between specific objects may direct some aspects of how these objects behave in the context of a user interface or how the objects are presented to a user.

As an example, in the context of the desktop of a computing device, the desktop may be a parent object, and sometimes the root object of a hierarchy, whose child objects are the individual software applications available on the desktop. A software application, while itself being one of the child objects of the desktop, is also the parent object of the individual components of that software application. Different software applications may include different components. For example, for a software application that manages digital books (e.g., a book reader application), its components may include the digital books available, the individual chapters of each book, the pages of each chapter, and the texts, images, videos, audios, or other content or media elements on each page. Each of these also corresponds to an object (e.g., user-interface component) in the hierarchy. More specifically, within the hierarchy, the digital book application may be the parent object of the digital books. A digital book may be the parent object of the individual chapters of that book. A chapter, while itself being one of the child objects of the book, is also the parent object of the pages in that chapter. A page is the parent object of the texts, images, videos, audios, or other content or media elements on that page. A text block, image, video, audio, or other content or media element is one of the child objects of the page to which it belongs. Similarly, for a software application that manages news feeds, its components may include the individual news channels and the news stories within each channel. Each of these may correspond to an object. Within the hierarchy, the news-feed application, while itself being one of the child objects of the desktop, is also the parent object of the news channels. A news channel in turn is the parent object of the news stories included in that channel.

As another example, in the context of the Internet or the World Wide Web, the Internet may be a parent object whose child objects are the individual websites. A website, while itself being one of the child objects of the Internet, is also the parent object of the individual web pages of that website. A web page, while itself being one of the child objects of the website to which it belongs, is the parent object of the texts, images, videos, audios, or links (e.g., Uniform Resource Locators (URLs)) included in the web page. Each text block, image, video, audio, or link may also correspond to a specific object in the hierarchy.

As a third example, a website, such as a social-networking website implemented by social-networking system 160, may also be arranged in a hierarchical structure for navigating the content of the social-networking website. In this context, the social-networking website may be a parent object whose child objects are the components (e.g., photo albums, user profile pages, etc.) of the website. For example, a photo album, while itself being a child object of the social-networking website, may in turn be a parent object, and the individual photos within the album may be the child objects of the photo album. A user's profile page may be structured in such a hierarchical fashion as well. The profile page itself may be considered a parent object, and the individual objects on the profile page may be the child objects of the profile page. In particular embodiments, a profile page may be considered and rendered (e.g., for presentation to a user) as a linear timeline of objects, such as, for example and without limitation, photos, photo albums, check-ins, comments from other users, attended events, tags, applications the user has added to the profile page, stories, songs the user has listened to, playlists. These various types of objects may all be children of the profile page, or may be further arranged into multiple levels. With some implementations, a user's profile page may include any number of sections, such as the user's education and employment information, the user's public “wall”, or the user's social connections. Then the various types of objects above may be divided into specific sections.

In particular embodiments, an object 410 may be a component of a user interface. In this case, object hierarchy 400 may correspond to the user interface, and each object 410 may correspond to a specific component of the user-interface. A user interface may have various types of components, and this disclosure contemplates any applicable user-interface component types. For example, a user-interface component (i.e., an object 410) may be a window, a section, a tab, an image, a video, an audio, a text block, a menu, an icon, a button, a checkbox, a website, a web page, a frame, a clickable link, a message, a post, or an input field. In particular embodiments, an object 410 may be consumed by a user if the user is able to, for example and without limitation, interact with, view, read, listen to, manipulate, or handle the object 410. For example, some user-consumable objects 410 may be texts, images, videos, audios, feeds, executables (e.g., application programs or games), websites, web pages, digital books, photo albums, posts, or messages.

In particular embodiments, when the user interface corresponding to object hierarchy 400 is displayed (e.g., on a client system 130), the structure of the corresponding object hierarchy 400 may reflect the structure of the user interface. The relationships among the individual components in the user interface, as reflected in object hierarchy 400, may influence how these components are organized and presented to users. The user interface may have any number of layers, respectively corresponding to the individual levels of object hierarchy 400. Objects 410 (e.g., user-interface components) at a specific level of object hierarchy 400 are displayed in the corresponding layer of the user interface. With some implementations, the lowest or bottommost layer of the user interface corresponds to the first or topmost level of object hierarchy 400. Thus, root object 410A is displayed in the lowest layer of the user interface. Furthermore, in the user interface, each object 410 (e.g., user-interface component) is displayed in a layer immediately above the layer where its parent, if one exists, is displayed and immediately below the layer where its children, if any, are displayed. Sibling objects 410 are displayed at the same layer. Thus, the position of a component in the user interface indicates its relationships (e.g., parent-child or sibling) with other components in the user interface.

In particular embodiments, a user-interface component (e.g., an image, a video, a folder, etc.) may be displayed in various display modes. As an example, the user-interface component may be displayed in a “full-screen” mode, where the user-interface component occupies the entire or nearly the entire display area (e.g., the screen of an electronic device). As another example, the user-interface component may be displayed in an “on-page” mode, where the user-interface component is included in another user-interface component and displayed as a part of that other user-interface component (e.g., an image is displayed as a part of a web page). As a third example, the user-interface component may be displayed in an “index” mode, where the user-interface component is a part of a series of user-interface components (e.g., an image is displayed together with other images from the same album, or a chapter of a book is displayed in the table of content of the book together with other chapters from the same book).

In particular embodiments, a hierarchical user interface may be used to present content to a user. Such a user interface may be referred to as a “content feed” or “news feed” user interface. The content may be of any type and format, such as, for example and without limitation, text, icon, image, video, audio, web page, post, or message. This disclosure contemplates any applicable content type and format. In particular embodiments, the individual content items (e.g., text, image, video, audio, web page, post, message, news piece, etc.) may be organized into various categories, referred to as content sections. For example, related content items may be categorized into the same content section. The user interface may include any number of content sections, and each content section may include any number of content items. Hierarchically, a content section may be the parent of the content items belonging to that section. For example, various photos taken during a holiday trip may be organized into the same album, and various photo albums may be organized into the photo section of the user interface.

In particular embodiments, a user may consume or interact with a specific content item. For example, a user consumes a content item when the user scrolls, opens up, views, listens to, selects, reviews, or comments on the content item. A user interacts with a content item when the user selects, clicks on, taps, reviews, or comments on the content item. This disclosure contemplates any applicable means for a user to consume or interact with a content item.

In particular embodiments, while a user is interacting with a computing device, such as a mobile device (e.g., Smartphone, tablet computer, etc.), from time to time, there may be event notifications displayed on the screen of the user's mobile device. These notifications may also be referred to as “tickers” or “visual tickers”. Each notification informs the user of an event that has occurred recently (e.g., within the past ten minutes, five minutes, one minute, thirty seconds, or ten seconds). Consequently, by presenting these notifications on the user's mobile device shortly after the corresponding events have occurred, the user is kept informed of the events that are occurring with near real-time notifications.

In particular embodiments, the events described in the notifications may be of particular interest to the user. For example, the notifications may describe breaking news, trendy or hot topics, social buzz, and so on. With some implementations, the user may be a member of a social-networking system and have friends (e.g., social connections) within the social-networking system. The notifications may describe actions taken by or activities conducted by the user's friends within the social-networking system. With some implementations, these actions or activities may be associated with the social-networking system. This enables the user to be notified of his friends' actions or activities, especially those actions or activities in connection with the social-networking system, in near real time.

On the other hand, the events described in the notifications are not necessarily related, per se, to the user's interactions with the mobile device at the time the notifications are received and displayed. For example, if, at the time an event notification is received and displayed on the mobile device, the user is making a telephone call, sending a text message, interacting with a native application, surfing the web, etc., the event described in the notification is not necessarily related, per se, to the telephone call, the text message, the native application, or the websites the user is visiting. With some implementations, there may be a native or web-based application that enables the user to interact with and perform actions in connection with the social-networking system through the user's mobile device. The user may receive the event notifications while interacting with such a social-networking application.

In particular embodiments, the user may control the specific types of events for which the user wishes to receive near real-time notifications. For example, the user may specify in the user's account settings with the social-networking system the types of events for which the user wishes to receive near real-time notifications (e.g., actions taken by friends, actions taken by friends of friends, actions concerning friends, breaking news, etc.). Thereafter, whenever or as soon as an event of the type selected by the user occurs, the social-networking system (e.g., through one of its servers) may send a notification of the event to the user's mobile device to be displayed on the screen of the device.

In particular embodiments, the notifications may be sent to and displayed on the user's mobile device automatically and without requiring the user to take any actions (e.g., making a request or query for the notifications, making a user input to the mobile device, etc.). In particular embodiments, after an event has occurred, as soon as possible (e.g., as soon as the social-networking system is notified or becomes aware of the event), the social-networking system may send a notification of the event to the user's mobile device (e.g., push the notification to the user's mobile device). If the user's mobile device is online at the time, the notification is displayed on the screen of the device as soon as it is received at the mobile device. If the user's mobile device is offline at the time, with some implementations, the notification may be saved in a queue (e.g., a temporary storage) and redelivered to the mobile device after the mobile device is back online. Then, the notification may be displayed on the screen of the device. Alternatively, with other implementations, the notification is discarded as it may no longer be relevant or of interest to the user by the time the mobile device is back online.

In particular embodiments, to display a notification, the notification may gradually appear (e.g., fade in) on the screen of the mobile device. The notification may remain on the screen for a period of time (e.g., sufficient for the user to notice and read the notification, such as five, ten, fifteen, or twenty seconds). Then the nonfiction may gradually disappear (e.g., fade out) from the screen of the mobile device. This entire process may take place automatically, without requiring the user to take any actions (e.g., making an input to the mobile device or interacting with the notification).

FIG. 5 illustrates an example event notification 510. Here, notification 510 is displayed on the screen of a Smartphone while the user is running and interacting with a social-networking application on the Smartphone. Notification 510 describes an action occurred recently (e.g., within the past thirty seconds), which concerns another user 504 (e.g., Mark Slee). User 504 may be a friend of the user of the Smartphone on which notification 510 is displayed. For example, user 504 and the user of the Smartphone may be friends within the social-networking system corresponding to the social-networking application.

Notification 510 includes the name of user 504, an icon 502, and a short description 506 of the action concerning user 504 (e.g., user 504 was tagged in a photo). With some implementations, the icon included in a notification corresponds to and represents the type of action described in the notification. In this example, icon 502 corresponds to the action of tagging a user in a photo.

FIG. 6 illustrates another example event notification 610. Notification 610 describes an action taken by another user 604 (e.g., Hwang Ic) recently. Similarly, notification 610 includes an icon 602, the name of user 604, and a short description 606 of the action taken by user 604 (e.g., user 604 recommended his own photo). Here, icon 602 corresponds to the action of making a user comment.

FIG. 7 illustrates a third example event notification 710. Notification 710 also describes an action taken by another user 704 (e.g., Keegan Jones) recently. Notification 710 includes an icon 702, the name of user 704, and a short description 706 of the action taken by user 704 (e.g., user 704 likes the check-in made by another user). Here, icon 702 corresponds to the action of liking something.

FIG. 8 illustrates a fourth example event notification 810. Notification 810 also describes an action taken by another user 804 (e.g., Leslee Kurihara) recently. Notification 810 includes an icon 802, the name of user 804, and a short description 806 of the action taken by user 804 (e.g., user 804 listens to some music). Here, icon 802 corresponds to the action of listing to some audio (e.g., music).

In particular embodiments, while a notification is displayed, an image relating to the event described in the notification may also be displayed at the same time on the screen of the mobile device (e.g., as a background image for the notification). For example, in FIG. 5, notification 510 describes that user 504 was tagged in a photo. Thus, the photo 520 where user 504 is tagged is displayed on the screen of the mobile device at the same time (e.g., as background image for the notification or the social-networking application). In FIG. 6, notification 610 describes that user 604 recommended his own photo. Here, the photo 620 recommended by user 504 is displayed on the screen of the mobile device at the same time. In FIG. 7, notification 710 describes that user 704 likes the check-in made by another user. Here, an image 720 representing the location where the check-in was made is displayed on the screen of the mobile device at the same time. In FIG. 8, notification 810 describes that user 804 listened to music by a specific artist. Here, an image 820 representing the artist is displayed on the screen of the mobile device at the same time.

Note that FIGS. 5-8 illustrate a specific format for the event notifications, which may be suitable for actions taken by or concerning users. This format includes an icon representing the type of action, a user's name, and a description of the action. Other formats for the event notifications may also be available and used (e.g., for different types of events), and this disclosure contemplates any suitable formats for the event notifications.

In particular embodiments, the event notifications received at a user's mobile device may be stored on the mobile device, at least for some period of time. The user may, at any time, review the notifications stored on the mobile device. For example, the user may cause the notifications to be displayed on the screen of the device by making a specific input (e.g., tapping the screen or clicking an icon).

In FIG. 9, an example series of notifications 900 received at and stored on a Smartphone is displayed. Here, notifications 900 are arranged in reverse chronological order, with the most-recent notifications displayed near the top of the series. Sometimes, not all available notifications may be displayed at the same time on the screen, due to the size limitation of the screen. In such cases, the user may scroll up or down through the series (e.g., by swiping up or down on the screen) to review the individual notifications 900.

The event notification functionalities may be implemented as computer software and executed on a computer system. FIG. 10 illustrates an example computer system 1000. In particular embodiments, one or more computer systems 1000 perform one or more steps of one or more methods described or illustrated herein. In particular embodiments, one or more computer systems 1000 provide functionality described or illustrated herein. In particular embodiments, software running on one or more computer systems 1000 performs one or more steps of one or more methods described or illustrated herein or provides functionality described or illustrated herein. Particular embodiments include one or more portions of one or more computer systems 1000. Herein, reference to a computer system may encompass a computing device, and vice versa, where appropriate. Moreover, reference to a computer system may encompass one or more computer systems, where appropriate.

This disclosure contemplates any suitable number of computer systems 1000. This disclosure contemplates computer system 1000 taking any suitable physical form. As example and not by way of limitation, computer system 1000 may be an embedded computer system, a system-on-chip (SOC), a single-board computer system (SBC) (such as, for example, a computer-on-module (COM) or system-on-module (SOM)), a desktop computer system, a laptop or notebook computer system, an interactive kiosk, a mainframe, a mesh of computer systems, a mobile telephone, a personal digital assistant (PDA), a server, a tablet computer system, or a combination of two or more of these. Where appropriate, computer system 1000 may include one or more computer systems 1000; be unitary or distributed; span multiple locations; span multiple machines; span multiple data centers; or reside in a cloud, which may include one or more cloud components in one or more networks. Where appropriate, one or more computer systems 1000 may perform without substantial spatial or temporal limitation one or more steps of one or more methods described or illustrated herein. As an example and not by way of limitation, one or more computer systems 1000 may perform in real time or in batch mode one or more steps of one or more methods described or illustrated herein. One or more computer systems 1000 may perform at different times or at different locations one or more steps of one or more methods described or illustrated herein, where appropriate.

In particular embodiments, computer system 1000 includes a processor 1002, memory 1004, storage 1006, an input/output (I/O) interface 1008, a communication interface 1010, and a bus 1012. Although this disclosure describes and illustrates a particular computer system having a particular number of particular components in a particular arrangement, this disclosure contemplates any suitable computer system having any suitable number of any suitable components in any suitable arrangement.

In particular embodiments, processor 1002 includes hardware for executing instructions, such as those making up a computer program. As an example and not by way of limitation, to execute instructions, processor 1002 may retrieve (or fetch) the instructions from an internal register, an internal cache, memory 1004, or storage 1006; decode and execute them; and then write one or more results to an internal register, an internal cache, memory 1004, or storage 1006. In particular embodiments, processor 1002 may include one or more internal caches for data, instructions, or addresses. This disclosure contemplates processor 1002 including any suitable number of any suitable internal caches, where appropriate. As an example and not by way of limitation, processor 1002 may include one or more instruction caches, one or more data caches, and one or more translation lookaside buffers (TLBs). Instructions in the instruction caches may be copies of instructions in memory 1004 or storage 1006, and the instruction caches may speed up retrieval of those instructions by processor 1002. Data in the data caches may be copies of data in memory 1004 or storage 1006 for instructions executing at processor 1002 to operate on; the results of previous instructions executed at processor 1002 for access by subsequent instructions executing at processor 1002 or for writing to memory 1004 or storage 1006; or other suitable data. The data caches may speed up read or write operations by processor 1002. The TLBs may speed up virtual-address translation for processor 1002. In particular embodiments, processor 1002 may include one or more internal registers for data, instructions, or addresses. This disclosure contemplates processor 1002 including any suitable number of any suitable internal registers, where appropriate. Where appropriate, processor 1002 may include one or more arithmetic logic units (ALUs); be a multi-core processor; or include one or more processors 1002. Although this disclosure describes and illustrates a particular processor, this disclosure contemplates any suitable processor.

In particular embodiments, memory 1004 includes main memory for storing instructions for processor 1002 to execute or data for processor 1002 to operate on. As an example and not by way of limitation, computer system 1000 may load instructions from storage 1006 or another source (such as, for example, another computer system 1000) to memory 1004. Processor 1002 may then load the instructions from memory 1004 to an internal register or internal cache. To execute the instructions, processor 1002 may retrieve the instructions from the internal register or internal cache and decode them. During or after execution of the instructions, processor 1002 may write one or more results (which may be intermediate or final results) to the internal register or internal cache. Processor 1002 may then write one or more of those results to memory 1004. In particular embodiments, processor 1002 executes only instructions in one or more internal registers or internal caches or in memory 1004 (as opposed to storage 1006 or elsewhere) and operates only on data in one or more internal registers or internal caches or in memory 1004 (as opposed to storage 1006 or elsewhere). One or more memory buses (which may each include an address bus and a data bus) may couple processor 1002 to memory 1004. Bus 1012 may include one or more memory buses, as described below. In particular embodiments, one or more memory management units (MMUs) reside between processor 1002 and memory 1004 and facilitate accesses to memory 1004 requested by processor 1002. In particular embodiments, memory 1004 includes random access memory (RAM). This RAM may be volatile memory, where appropriate Where appropriate, this RAM may be dynamic RAM (DRAM) or static RAM (SRAM). Moreover, where appropriate, this RAM may be single-ported or multi-ported RAM. This disclosure contemplates any suitable RAM. Memory 1004 may include one or more memories 1004, where appropriate. Although this disclosure describes and illustrates particular memory, this disclosure contemplates any suitable memory.

In particular embodiments, storage 1006 includes mass storage for data or instructions. As an example and not by way of limitation, storage 1006 may include a hard disk drive (HDD), a floppy disk drive, flash memory, an optical disc, a magneto-optical disc, magnetic tape, or a Universal Serial Bus (USB) drive or a combination of two or more of these. Storage 1006 may include removable or non-removable (or fixed) media, where appropriate. Storage 1006 may be internal or external to computer system 1000, where appropriate. In particular embodiments, storage 1006 is non-volatile, solid-state memory. In particular embodiments, storage 1006 includes read-only memory (ROM). Where appropriate, this ROM may be mask-programmed ROM, programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), electrically alterable ROM (EAROM), or flash memory or a combination of two or more of these. This disclosure contemplates mass storage 1006 taking any suitable physical form. Storage 1006 may include one or more storage control units facilitating communication between processor 1002 and storage 1006, where appropriate. Where appropriate, storage 1006 may include one or more storages 1006. Although this disclosure describes and illustrates particular storage, this disclosure contemplates any suitable storage.

In particular embodiments, I/O interface 1008 includes hardware, software, or both, providing one or more interfaces for communication between computer system 1000 and one or more I/O devices. Computer system 1000 may include one or more of these I/O devices, where appropriate. One or more of these I/O devices may enable communication between a person and computer system 1000. As an example and not by way of limitation, an I/O device may include a keyboard, keypad, microphone, monitor, mouse, printer, scanner, speaker, still camera, stylus, tablet, touch screen, trackball, video camera, another suitable I/O device or a combination of two or more of these. An I/O device may include one or more sensors. This disclosure contemplates any suitable I/O devices and any suitable I/O interfaces 1008 for them. Where appropriate, I/O interface 1008 may include one or more device or software drivers enabling processor 1002 to drive one or more of these I/O devices. I/O interface 1008 may include one or more I/O interfaces 1008, where appropriate. Although this disclosure describes and illustrates a particular I/O interface, this disclosure contemplates any suitable I/O interface.

In particular embodiments, communication interface 1010 includes hardware, software, or both providing one or more interfaces for communication (such as, for example, packet-based communication) between computer system 1000 and one or more other computer systems 1000 or one or more networks. As an example and not by way of limitation, communication interface 1010 may include a network interface controller (NIC) or network adapter for communicating with an Ethernet or other wire-based network or a wireless NIC (WNIC) or wireless adapter for communicating with a wireless network, such as a WI-FI network. This disclosure contemplates any suitable network and any suitable communication interface 1010 for it. As an example and not by way of limitation, computer system 1000 may communicate with an ad hoc network, a personal area network (PAN), a local area network (LAN), a wide area network (WAN), a metropolitan area network (MAN), or one or more portions of the Internet or a combination of two or more of these. One or more portions of one or more of these networks may be wired or wireless. As an example, computer system 1000 may communicate with a wireless PAN (WPAN) (such as, for example, a BLUETOOTH WPAN), a WI-FI network, a WI-MAX network, a cellular telephone network (such as, for example, a Global System for Mobile Communications (GSM) network), or other suitable wireless network or a combination of two or more of these. Computer system 1000 may include any suitable communication interface 1010 for any of these networks, where appropriate. Communication interface 1010 may include one or more communication interfaces 1010, where appropriate. Although this disclosure describes and illustrates a particular communication interface, this disclosure contemplates any suitable communication interface.

In particular embodiments, bus 1012 includes hardware, software, or both coupling components of computer system 1000 to each other. As an example and not by way of limitation, bus 1012 may include an Accelerated Graphics Port (AGP) or other graphics bus, an Enhanced Industry Standard Architecture (EISA) bus, a front-side bus (FSB), a HYPERTRANSPORT (HT) interconnect, an Industry Standard Architecture (ISA) bus, an INFINIBAND interconnect, a low-pin-count (LPC) bus, a memory bus, a Micro Channel Architecture (MCA) bus, a Peripheral Component Interconnect (PCI) bus, a PCI-Express (PCIe) bus, a serial advanced technology attachment (SATA) bus, a Video Electronics Standards Association local (VLB) bus, or another suitable bus or a combination of two or more of these. Bus 1012 may include one or more buses 1012, where appropriate. Although this disclosure describes and illustrates a particular bus, this disclosure contemplates any suitable bus or interconnect.

Herein, a computer-readable non-transitory storage medium or media may include one or more semiconductor-based or other integrated circuits (ICs) (such, as for example, field-programmable gate arrays (FPGAs) or application-specific ICs (ASICs)), hard disk drives (HDDs), hybrid hard drives (HHDs), optical discs, optical disc drives (ODDs), magneto-optical discs, magneto-optical drives, floppy diskettes, floppy disk drives (FDDs), magnetic tapes, solid-state drives (SSDs), RAM-drives, SECURE DIGITAL cards or drives, any other suitable computer-readable non-transitory storage media, or any suitable combination of two or more of these, where appropriate. A computer-readable non-transitory storage medium may be volatile, non-volatile, or a combination of volatile and non-volatile, where appropriate.

Herein, “or” is inclusive and not exclusive, unless expressly indicated otherwise or indicated otherwise by context. Therefore, herein, “A or B” means “A, B, or both,” unless expressly indicated otherwise or indicated otherwise by context. Moreover, “and” is both joint and several, unless expressly indicated otherwise or indicated otherwise by context. Therefore, herein, “A and B” means “A and B, jointly or severally,” unless expressly indicated otherwise or indicated otherwise by context.

The scope of this disclosure encompasses all changes, substitutions, variations, alterations, and modifications to the example embodiments described or illustrated herein that a person having ordinary skill in the art would comprehend. The scope of this disclosure is not limited to the example embodiments described or illustrated herein. Moreover, although this disclosure describes and illustrates respective embodiments herein as including particular components, elements, functions, operations, or steps, any of these embodiments may include any combination or permutation of any of the components, elements, functions, operations, or steps described or illustrated anywhere herein that a person having ordinary skill in the art would comprehend. Furthermore, reference in the appended claims to an apparatus or system or a component of an apparatus or system being adapted to, arranged to, capable of, configured to, enabled to, operable to, or operative to perform a particular function encompasses that apparatus, system, component, whether or not it or that particular function is activated, turned on, or unlocked, as long as that apparatus, system, or component is so adapted, arranged, capable, configured, enabled, operable, or operative. 

What is claimed is:
 1. A computer-implemented method comprising: while a first user is interacting with a mobile device, selecting a notification to be displayed on a screen of the mobile device automatically and without any user input to the mobile device, wherein the displayed notification is selected based on one or more types of events predetermined by the first user, wherein the first user is represented by a first node in a social graph of a social-networking system, the social graph comprising a plurality of nodes and edges connecting the nodes, wherein the displayed notification comprises information about an event that has occurred recently and is not related to the user's interaction with the mobile device, and wherein the types of events predetermined by the first user comprises notifications selected based on a relationship represented by a connection between the first user and a second user corresponding to a second node in the social graph of the social-networking system; while the notification is being displayed on the screen, displaying, concurrently with the notification, an image relating to the event as a background image on the screen of the mobile device, wherein the background image is displayed on a first layer, and the notification is displayed on a second layer different from the first layer, and wherein the notification displayed on the second layer is displayed to overlay the background image displayed on the first layer; and automatically removing the notification from the screen after a predetermined amount of time.
 2. The method of claim 1, wherein the event has occurred within one minute from when the notification is displayed.
 3. The method of claim 1, wherein when the notification is displayed on the screen, the notification gradually appears on the screen over a first period of time, and wherein when the notification is removed, the notification is displayed to gradually disappear on the screen over a second period of time.
 4. The method of claim 3, wherein the event comprises a recent action taken by or concerning the second user; and wherein the notification comprises: an icon indicating a type of the action; a name of the second user; and a description of the action.
 5. The method of claim 1, further comprising receiving the notification from a server associated with a social-networking system.
 6. The method of claim 1, further comprising in response to a user input, displaying a plurality of most-recent notifications on the screen of the mobile device, the most-recent notifications being arranged in reverse chronological order.
 7. One or more computer-readable non-transitory storage media embodying software that is operable when executed to: while a first user is interacting with a mobile device, select a notification to be displayed on a screen of the mobile device automatically and without any user input to the mobile device, wherein the displayed notification is selected based on one or more types of events predetermined by the first user, wherein the first user is represented by a first node in a social graph of a social-networking system, the social graph comprising a plurality of nodes and edges connecting the nodes, wherein the displayed notification comprises information about an event that has occurred recently and is not related to the user's interaction with the mobile device, and wherein the types of events predetermined by the first user comprises notifications selected based on a relationship represented by a connection between the first user and a second user corresponding to a second node in the social graph of the social-networking system; while the notification is being displayed on the screen, display, concurrently with the notification, an image relating to the event as a background image on the screen of the mobile device, wherein the background image is displayed on a first layer, and the notification is displayed on a second layer different from the first layer, and wherein the notification displayed on the second layer is displayed to overlay the background image displayed on the first layer; and automatically remove the notification from the screen after a predetermined amount of time.
 8. The media of claim 7, wherein the event has occurred within one minute from when the notification is displayed.
 9. The media of claim 7, wherein when the notification is displayed on the screen, the notification gradually appears on the screen over a first period of time, and wherein when the notification is removed, the notification is displayed to gradually disappear on the screen over a second period of time.
 10. The media of claim 9, wherein the event comprises a recent action taken by or concerning the second user; and wherein the notification comprises: an icon indicating a type of the action; a name of the second user; and a description of the action.
 11. The media of claim 7, wherein the software is further operable when executed to receive the notification from a server associated with a social-networking system.
 12. The media of claim 7, wherein the software is further operable when executed to in response to a user input, display a plurality of most-recent notifications on the screen of the mobile device, the most-recent notifications being arranged in reverse chronological order.
 13. A system comprising: one or more processors; and a memory coupled to the processors comprising instructions executable by the processors, the processors operable when executing the instructions to: while a first user is interacting with a mobile device, select a notification to be displayed on a screen of the mobile device automatically and without any user input to the mobile device, wherein the displayed notification is selected based on one or more types of events predetermined by the first user, wherein the first user is represented by a first node in a social graph of a social-networking system, the social graph comprising a plurality of nodes and edges connecting the nodes, wherein the displayed notification comprises information about an event that has occurred recently and is not related to the user's interaction with the mobile device, and wherein the types of events predetermined by the first user comprises notifications selected based on a relationship represented by a connection between the first user and a second user corresponding to a second node in the social graph of the social-networking system; and while the notification is being displayed on the screen, display, concurrently with the notification, an image relating to the event as a background image on the screen of the mobile device, wherein the background image is displayed on a first layer, and the notification is displayed on a second layer different from the first layer, and wherein the notification displayed on the second layer is displayed to overlay the background image displayed on the first layer; and automatically remove the notification from the screen after a predetermined amount of time.
 14. The system of claim 13, wherein the event has occurred within one minute from when the notification is displayed.
 15. The system of claim 13, wherein when the notification is displayed on the screen, the notification gradually appears on the screen over a first period of time, and wherein when the notification is removed, the notification is displayed to gradually disappear on the screen over a second period of time.
 16. The system of claim 15, wherein the notification comprises: an icon indicating a type of the action; a name of the second user; and a description of the action.
 17. The system of claim 13, wherein the processors are further operable when executing the instructions to in response to a user input, display a plurality of most-recent notifications on the screen of the mobile device, the most-recent notifications being arranged in reverse chronological order. 